transition

(noun) the act of passing from one state or place to the next. Synonyms: passage.

(noun) an event that results in a transformation. Synonyms: conversion, changeover.

(noun) a change from one place or state or subject or stage to another.

(noun) a musical passage moving from one key to another. Synonyms: modulation.

(noun) a passage that connects a topic to one that follows.

(verb) cause to convert or undergo a transition. Example: "The company had to transition the old practices to modern technology."

(verb) make or undergo a transition (from one state or system to another). Examples: "The airline transitioned to more fuel-efficient jets." "The adagio transitioned into an allegro."